pbody -
When you say Roadster S, I will assume you mean Roadster Sport.
There are several factors that will impact the car's value and potential sales price, such as mileage (which you have disclosed) and condition, but also options. In the case of a Roadster, those options are not insignificant (e.g., carbon hard top, charger, interior, infotainment, battery replacement, expended warranty). But as a general matter, you can see some comparables here:
Tesla : Roadster Sport 2.5 sport convertible in Tesla | eBay Motors
This car got no bids at $98K, but it is probably inferior to your subject vehicle (e.g., wheels, more miles). I'd probably infer an indicated value of yours of something a bit higher, given the mileage (though we don't know the options).
#1121 - Arctic White - Seattle, WA
Not a sport, and overpriced at $97K. Base wheels. Probably worth more like $80-$85K.
As an appraiser, you can appreciate the challenge of valuation premises and the definition of fair market value - willing buyer, willing seller, each with knowledge of relevant info, neither under compulsion to transact. In the case of real world transactions, that is not always a fair assumption. Sellers are usually selling for a reason, and sometimes they are more desperate, so prices fall. In my case, I'm in no mood to sell, and I dig my car, so you would have to pay me $150K for it. But if I were to sell it I think I would have a hard time getting $100K. Value is what someone is willing to pay, assuming a seller is willing to sell for that. That is strongly influenced by each side's BATNA.
Here a relevant example:
Last chance at 2011 Roadster 2.5 #1196, Thunder Gray, 19K miles, $75K - Denver, CO
The owner/seller is getting rid of the car. He can return it to Tesla for something around $80K. So he will sell is for $82K. It isn't a Sport. 19K miles. Base model (e.g., less expensive wheels).
Of course, all of the listings I include are not sales prices, as you noted. But the first and third are low offer prices. I expect them to sell for about those prices. If your subject vehicle is a Sport, it is likely worth a bit more than $100K, depending on options.
And finally, all of my analysis is of CURRENT PRICES. In early 2012 prices were a bit higher. I'd add $5K-$10K for your car for that valuation date.
Good luck in your appraisal!
